Just threw a battery in my 88 Cherokee that’s been sitting for about 10 months. The engine is blown but I wanted to see if it would still turn over. When I hook the battery up the lights come on in the car, but when I turn the key it just has one clunk from the starter and then all the lights go out. They won’t come back on until I disconnect and reconnect the battery. Any clues? I understand if the engine is seized, but I would expect the lights to come back on when I stop turning the key

I get that same symptom when the battery terminals are loose and corroded. There are other possible causes of that symptom but 99 times out of 100 that's what it was. Never mattered what year or brand of car/truck either.

Yep. That's classic bad connection behavior. Could be the terminals, the cables themselves, or even internal to the battery.

Most likely one or more of the grounds in the engine compartment is corroded and has a bad connection. With a “blown” motor, this is the least of the problems.